<template>
  <div class="app-container">
    <!--查询表单-->
    <el-form :inline="true" class="demo-form-inline">

      <!-- 所属分类：级联下拉列表 -->
      <!-- 一级分类 -->
      <el-form-item label="课程类别">
        <el-select
          v-model="courseInfoVo.subjectParentId"
          placeholder="请选择"
          @change="subjectLevelOneChanged">
          <el-option
            v-for="subject in subjectNestedList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfoVo.subjectId" placeholder="请选择">
          <el-option
            v-for="subject in subSubjectList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>

      <!-- 标题 -->
      <el-form-item>
        <el-input v-model="courseInfoVo.title" placeholder="课程标题"/>
      </el-form-item>
      <!-- 讲师 -->
      <el-form-item>
        <el-select
          v-model="courseInfoVo.teacherId"
          placeholder="请选择讲师">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>

      <el-button type="primary" icon="el-icon-search" @click="getPageList()">查询</el-button>
      <el-button type="default" @click="resetData()">清空</el-button>
    </el-form>

    <!-- 表格 -->
    <el-table
      v-loading="listLoading"
      :data="list"
      element-loading-text="数据加载中"
      border
      fit
      highlight-current-row
      row-class-name="myClassList">

      <el-table-column
        label="序号"
        width="70"
        align="center">
        <template slot-scope="scope">
          {{ (page - 1) * limit + scope.$index + 1 }}
        </template>
      </el-table-column>

      <el-table-column label="课程信息" width="470" align="center">
        <template slot-scope="scope">
          <div class="info">
            <div class="pic">
              <img :src="scope.row.cover" alt="scope.row.title" width="150px">
            </div>
            <div class="title">
              <router-link :to="'/edu/course/publish/'+scope.row.id">
                <el-button type="text" size="mini" >{{ scope.row.title }}</el-button>
              </router-link>
              <p>{{ scope.row.lessonNum }}课时</p>
            </div>
          </div>

        </template>
      </el-table-column>

      <el-table-column label="创建时间" align="center">
        <template slot-scope="scope">
          {{ scope.row.gmtCreate.substr(0, 10) }}
        </template>
      </el-table-column>
      <el-table-column label="发布时间" align="center">
        <template slot-scope="scope">
          {{ scope.row.gmtModified.substr(0, 10) }}
        </template>
      </el-table-column>
      <el-table-column label="价格" width="100" align="center">
        <template slot-scope="scope">
          {{
            Number(scope.row.price) === 0 ? '免费' :
              '¥' + scope.row.price.toFixed(2)
          }}
        </template>
      </el-table-column>
      <el-table-column prop="buyCount" label="付费学员" width="100" align="center">
        <template slot-scope="scope">
          {{ scope.row.buyCount }}人
        </template>
      </el-table-column>

      <el-table-column label="操作" width="150" align="center">
        <template slot-scope="scope">
          <router-link :to="'/edu/course/info/'+scope.row.id">
            <el-button type="text" size="mini" icon="el-icon-edit">编辑课程信息</el-button>
          </router-link>
          <router-link :to="'/edu/course/chapter/'+scope.row.id">
            <el-button type="text" size="mini" icon="el-icon-edit">编辑课程大纲</el-button>
          </router-link>
          <el-button type="text" size="mini" icon="el-icon-delete" @click="removeDataById(scope.row.id)">删除</el-button>
        </template>
      </el-table-column>
    </el-table>

    <!-- 分页 -->
    <el-pagination
      :current-page="page"
      :page-size="limit"
      :total="total"
      style="padding: 30px 0; text-align: center;"
      layout="total, prev, pager, next, jumper"
      @current-change="getPageList"
    />
  </div>
</template>

<script>
  // 引入调用
  import course from '@/api/edu/course'
  import teacher from '@/api/edu/teacher'
  import subject from '@/api/edu/subject'

  export default {
    // 写核心代码
    data() {
      return {
        listLoading: true, // 是否显示loading信息
        list: null, // 数据列表
        total: 0, // 总记录数
        page: 1, // 页码
        limit: 10, // 每页记录数
        courseInfoVo: {
          subjectParentId: '',
          subjectId: '',
          title: '',
          teacherId: ''
        }, // 查询条件
        teacherList: [], // 讲师列表
        subjectNestedList: [], // 一级分类列表
        subSubjectList: [] // 二级分类列表,
      }
    },
    methods: {
      // 根据id删除课程
      removeDataById(id) {
        // 提示框
        this.$confirm('此操作将永久删除此记录, 是否继续?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }).then(() => {
          // 点击确定后删除
          course.removeById(id)
            .then((response) => {
              if (response.code == 20000) {
                // 提示成功
                this.$message({
                  type: 'success',
                  message: '删除成功!'
                })
                // 回到列表页面
                this.getPageList()
              }
            })
        })
      },
      // 分页列表
      getPageList(page = 1) {
        this.page = page
        this.listLoading = true
        course.getPageList(this.page, this.limit, this.courseInfoVo).then(response => {
          this.list = response.data.rows
          this.total = response.data.total
          this.listLoading = false
        })
      },
      // 初始化老师
      initTeacherList() {
        teacher.getList().then(response => {
          this.teacherList = response.data.items
        })
      },
      // 初始化课程分类
      initSubjectList() {
        subject.getNestedTreeList().then(response => {
          this.subjectNestedList = response.data.items
        })
      },
      // 课程二级分类
      subjectLevelOneChanged(value) {
        for (let i = 0; i < this.subjectNestedList.length; i++) {
          if (this.subjectNestedList[i].id === value) {
            this.subSubjectList = this.subjectNestedList[i].children
            this.courseInfoVo.subjectId = ''
          }
        }
      },
      resetData() {
        this.courseInfoVo = {}
        this.subSubjectList = [] // 二级分类列表
        this.getPageList()
      }
    },
    created() {
      // 分页列表
      this.getPageList()
      // 初始化分类列表
      this.initSubjectList()
      // 获取讲师列表
      this.initTeacherList()
    }
  }
</script>
<style scoped>
  .myClassList .info {
    width: 450px;
    overflow: hidden;
  }

  .myClassList .info .pic {
    width: 150px;
    height: 90px;
    overflow: hidden;
    float: left;
  }

  .myClassList .info .pic a {
    display: block;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }

  .myClassList .info .pic img {
    display: block;
    width: 100%;
  }

  .myClassList td .info .title {
    width: 280px;
    float: right;
    height: 90px;
  }

  .myClassList td .info .title a {
    display: block;
    height: 48px;
    line-height: 24px;
    overflow: hidden;
    color: #00baf2;
    margin-bottom: 12px;
  }

  .myClassList td .info .title p {
    line-height: 20px;
    margin-top: 5px;
    color: #818181;
  }
</style>
